tACS for Aphasia

Overseen By Denise Harvey, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Pennsylvania

Disqualifiers: Neurological disorders, Psychiatric disorders, Alcohol/drug abuse, others

Compensation: Varies

Number of Visits: 1

Duration: 1 session

120 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if transcranial alternating current stimulation (tACS) can improve language abilities in individuals with aphasia following a stroke. Participants will receive either real or sham tACS while engaging in language tasks, such as sentence completion and verb generation. The trial seeks individuals who have experienced a single stroke on the left side of the brain and continue to have language difficulties six months afterward. As an unphased trial, this study provides a unique opportunity to contribute to groundbreaking research that could enhance language recovery methods.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, if you have a history of significant or poorly controlled psychiatric disorders or current abuse of alcohol or drugs, you may not be eligible to participate.

What prior data suggests that tACS is safe for enhancing language abilities in people with post-stroke aphasia?

Research shows that transcranial alternating current stimulation (tACS) is generally safe. Past studies demonstrated that tACS helps stroke patients recover more effectively. Importantly, these studies did not find any serious side effects. Most people tolerate tACS well, with mild side effects such as slight itching or tingling on the scalp. This suggests that tACS is a well-tolerated treatment option for improving language skills in those with post-stroke aphasia. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike standard treatments for aphasia, which often rely on speech therapy and medications, transcranial alternating current stimulation (tACS) offers a unique approach by using electrical currents to stimulate brain activity. Researchers are particularly excited about tACS because it delivers alternating currents in the alpha frequency band, which may enhance language processing by directly influencing brain waves. This method is non-invasive and can be precisely targeted, potentially providing a new avenue for improving language skills in people with aphasia.

What evidence suggests that tACS is effective for enhancing language abilities in post-stroke aphasia?

Research shows that transcranial alternating current stimulation (tACS) might improve language skills in people with speech difficulties after a stroke. This trial will assign participants to receive either real-tACS or sham-tACS. An earlier study found that those who received tACS had better speech understanding and increased blood flow in their brains. This suggests that tACS could enhance brain function to aid in recovering language skills. Although the results are promising, further studies are needed to confirm its effectiveness specifically for language problems after a stroke. Overall, tACS appears to offer a new method to help stroke survivors regain their ability to speak. ^{1 2 3 6 7}

Are You a Good Fit for This Trial?

This trial is for right-handed individuals who have had a stroke in the left hemisphere of their brain at least 6 months ago and are now experiencing aphasia, which affects language abilities. They must understand the study and agree to participate.

Inclusion Criteria

Must be able to understand the nature of the study, and give informed consent

My stroke happened more than 6 months ago.

I have difficulty with speaking or understanding language.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive real and sham transcranial alternating current stimulation (tACS) in conjunction with language tests

1 session

1 visit (in-person)

Follow-up

Participants are monitored for language performance improvement and brain response to tACS

5-10 minutes after treatment

What Are the Treatments Tested in This Trial?

Interventions

• tACS

Trial Overview Researchers are testing if active transcranial alternating current stimulation (tACS) can improve language skills in people with post-stroke aphasia. Participants will undergo real and sham tACS while performing language tests to measure effectiveness.

How Is the Trial Designed?

Group I: real-tACS Active Control 1 Intervention

The active stimulation will consist of an alternating current delivered in the alpha frequency band with a peak-to-peak intensity of 4 milliamps (mA) for 20 minutes. Participants will complete sentence completion and verb generation task during stimulation.

Group II: sham-tACS Placebo Group 1 Intervention

Sham stimulation involves the delivery of 60 seconds of the actual stimulation waveform ("ramp up") which is then gradually reduced to 0 milliamps (mA) ("ramp down"). Participants will complete sentence completion and verb generation task during stimulation.

Who Is Running the Clinical Trial?

University of Pennsylvania

Lead Sponsor

Trials

2,118

Recruited

45,270,000+

Published Research Related to This Trial

A systematic review of five trials with 54 participants found no evidence that transcranial direct current stimulation (tDCS) improves speech and language therapy outcomes for stroke patients with aphasia.

While no adverse events were reported, the studies primarily measured picture naming rather than real-life communication, and cathodal tDCS over the non-lesioned hemisphere showed potential as a promising approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients after stroke. Elsner, B., Kugler, J., Pohl, M., et al.[2022]

In a study of 37 stroke patients, speech therapy combined with transcranial direct current stimulation (tDCS) significantly improved language function, with an average increase in aphasia quotient (AQ%) of 14.94% after treatment.

Patients with less severe, fluent types of aphasia who started treatment within 30 days of their stroke showed the best responses, and those with hemorrhagic strokes had a higher likelihood of improvement compared to those with infarctions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients. Jung, IY., Lim, JY., Kang, EK., et al.[2021]

Transcranial direct current stimulation (tDCS) combined with language training showed improved verb production in a 43-year-old male with fluent-anomic aphasia after a stroke, suggesting enhanced language recovery.

The study indicates that using tDCS over Broca's area during language therapy may effectively support brain plasticity and improve language skills in individuals with aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Translational treatment of aphasia combining neuromodulation and behavioral intervention for lexical retrieval: implications from a single case study. Galletta, EE., Vogel-Eyny, A.[2020]

Transcranial direct-current stimulation (tDCS) significantly improved articulatory accuracy in patients with aphasia after stroke, indicating its potential effectiveness in enhancing speech production.

While tDCS showed qualitative improvements in naming and syllable repetition tasks, these results were not statistically significant, suggesting that further research is needed to fully understand its impact.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodal tDCS on Articulatory Accuracy, Word Production, and Syllable Repetition in Subjects with Aphasia: A Crossover, Double-Blinded, Sham-Controlled Trial. Vila-Nova, C., Lucena, PH., Lucena, R., et al.[2021]

Transcranial direct current stimulation (tDCS) applied to the left inferior frontal gyrus significantly improved language abilities in patients with nonfluent poststroke aphasia when combined with speech language therapy, as shown by a higher Aphasia Quotient in the A-tDCS group compared to the sham group (72.99 vs. 46.18).

The study involved 18 patients over four weeks, with results indicating that tDCS enhances the effectiveness of speech language therapy, particularly in areas other than comprehension, suggesting a beneficial mechanism of action for language recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodic Transcranial Direct Current Stimulation Combined With Speech Language Therapy on Nonfluent Poststroke Aphasia. Zhao, Q., Wang, J., Li, Z., et al.[2022]

In a study involving 11 chronic stroke patients with aphasia, dual transcranial direct current stimulation (tDCS) showed a significant improvement in naming response times compared to baseline, suggesting enhanced efficacy over single tDCS.

Both single and dual tDCS improved the number of correct responses in naming tasks, but dual tDCS, which targeted both the left and right inferior frontal gyri, may offer greater benefits for language recovery in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients. Lee, SY., Cheon, HJ., Yoon, KJ., et al.[2021]

In a study of 58 right-handed English speakers with subacute aphasia, transcranial direct-current stimulation (tDCS) did not significantly enhance picture naming accuracy compared to sham treatment, indicating limited efficacy for this specific outcome.

However, tDCS was associated with greater improvements in discourse skills, which are important for communication, and no adverse events were reported, suggesting it is a safe adjunct to language therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial Direct-Current Stimulation in Subacute Aphasia: A Randomized Controlled Trial. Stockbridge, MD., Elm, J., Breining, BL., et al.[2023]

In a study involving eight patients with aphasia, bihemispheric transcranial direct current stimulation (tDCS) combined with intensive language therapy led to significant improvements in language tasks, including articulation accuracy and speed, after just 10 days of treatment.

The positive effects of this bihemispheric stimulation persisted even one week after treatment, suggesting that this method may enhance recovery in chronic aphasia patients more effectively than previous unihemispheric approaches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bihemispheric stimulation over left and right inferior frontal region enhances recovery from apraxia of speech in chronic aphasia. Marangolo, P., Fiori, V., Cipollari, S., et al.[2013]

In a study involving 10 individuals undergoing standard aphasia therapy, 70% expressed interest in and were eligible for transcranial direct current stimulation (tDCS), which was administered during therapy sessions.

Data from four participants showed a large effect size (Cohen's d = 1.32) favoring active tDCS over sham stimulation, suggesting that tDCS may enhance communication outcomes in aphasia therapy, although one participant with severe deficits did not benefit.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical Feasibility of Combining Transcranial Direct Current Stimulation with Standard Aphasia Therapy. Duncan, ES., Nakkawita, SG.[2022]

A systematic review of 25 studies involving 471 participants found that Transcranial Direct Current Stimulation (tDCS) did not improve overall functional communication in stroke patients, indicating limited efficacy for this primary outcome.

However, anodal tDCS, especially when applied over the left inferior frontal gyrus, showed a significant improvement in noun naming performance, suggesting it may be a promising targeted treatment for specific language deficits after stroke.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia after stroke: a systematic review with network meta-analysis of randomized controlled trials. Elsner, B., Kugler, J., Mehrholz, J.[2020]

In a study involving 37 participants with moderate to severe aphasia, repeated anodal transcranial direct current stimulation (A-tDCS) did not show a significant positive impact on language recovery when combined with language therapy, compared to a sham stimulation group.

Both groups showed improvement in language abilities after therapy, but there were no statistically significant differences in outcomes between the A-tDCS and control groups, indicating that A-tDCS may not provide functional benefits in early post-stroke rehabilitation for aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

No effects of anodal transcranial direct stimulation on language abilities in early rehabilitation of post-stroke aphasic patients. Polanowska, KE., Leśniak, M., Seniów, JB., et al.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10805992/

The effect of transcranial alternating current stimulation on ... The results demonstrated that the tACS group had a significant decrease in mean NIHSS scores, a larger increase in blood flow velocity, and a ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT04375722

Transcranial Alternating Current Stimulation (tACS) in ... This study will assess the effects of transcranial alternating current stimulation (tACS) on language recovery after stroke as well as healthy language ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S2666459325000885

Effect of transcranial direct current stimulation combined ... tDCS combined with SLT demonstrates potential enhancement in language recovery on post-ischemic stroke aphasia. The combination may augment speech content, ...

4. brainstimjrnl.com brainstimjrnl.com/article/S1935-861X(22)00245-5/fulltext

A single-blind sham-controlled study - Brain Stimulation We predicted that tACS over SMA would enhance the efficacy of SLT in chronic post-stroke aphasia, especially for improving speech comprehension.

5. centerwatch.com centerwatch.com/clinical-trials/listings/NCT04375722/transcranial-alternating-current-stimulation-tacs-in-aphasia

Transcranial Alternating Current Stimulation (tACS) in ... This study will assess the effects of transcranial alternating current stimulation (tACS) on language recovery after stroke as well as healthy ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT06092814

NCT06092814 | tACS to Enhance Language Abilities The goal of this study is to see if transcranial alternating current stimulation (tACS) can be used to enhance language abilities in people with post-stroke ...

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5389927/

Safety Review of transcranial Direct Current Stimulation in ... Only 11.62% of published papers reported the occurrence of tDCS adverse effects in stroke patients. The most common was itching (70%), followed by burning ...